TWI610983B - Method of poly(1,4-cyclohexylenedimethylene terephthalate) having enhanced colors, and poly(1,4-cyclohexylenedimethylene terephthalate) manufactured by the same - Google Patents

Abstract

The preparation method of the polycyclohexane terephthalate resin according to the present invention includes the steps of injecting a titanium compound and a germanium compound as a catalyst into a mixture of a diol compound and a dicarboxylic acid under stirring, and performing Esterification reaction and polycondensation reaction, in which the titanium atom content of the injected titanium compound is 20 ppm or less, based on the weight of the final polycyclohexane terephthalate resin. According to the method for preparing polycyclohexane terephthalate resin of the present invention, it can be used to prepare polycyclohexane terephthalate resin with excellent degree of polymerization, color and light reflectivity, and has significantly improved thermal stability It is suitable for LED housing materials.

Description

Method for enhancing the color of poly (1,4-cyclohexane dimethyl terephthalate) and the resulting poly (1,4-cyclohexane dimethyl terephthalate)

The invention relates to a preparation method of polycyclohexane terephthalate resin, and a polycyclohexane terephthalate resin prepared by this method. More specifically, the present invention relates to a method for preparing a polycyclohexane terephthalate resin excellent in color, and a polycyclohexane terephthalate resin prepared by this method.

Polyalkyl terephthalate has excellent physical properties such as wear resistance, durability, thermal stability, etc., and thus has been used as a material for manufacturing fibers, films, and molded products. Poly (ethylene terephthalate) (hereinafter referred to as "PET"), poly (butylene terephthalate) (hereinafter referred to as "PBT"), and cyclohexane dimethyl terephthalate (poly ( Terephthalic acid-1,4-cyclohexane dimethyl ester), hereinafter referred to as "PCT") is a commercial grade polyalkyl terephthalate. Among them, the most widely used commercial material is PET, and it is mainly used in fibers, bottles, or the like.

Despite its excellent physical properties, because of its relatively low crystallization rate, if it is used as an engineering plastic with high crystallinity, PET requires nucleating agents and crystallization accelerators as processing aids, so the production rate becomes lower, or in During the injection molding process, the temperature of the mold must be controlled to maintain a high crystallization rate.

At the same time, since PBT has a higher crystallization rate than PET, it overcomes the aforementioned physical property problems of PET used in engineering plastics, namely low crystallinity, and thus has been widely used in engineering plastics. However, PBT has a lower heat deflection temperature than PET, so its application in applications requiring high heat resistance is limited, although its formability is superior to PET.

At the same time, PCT is prepared as a new material that can overcome the above problems of polyester materials Of concern, that is, the problem of moldability due to the slow crystallization rate, and the limited application due to the low heat deflection temperature.

Such PCT is a kind of terephthalic acid (hereinafter referred to as TPA) or terephthalic acid Crystalline polyester prepared by esterification or lactide reaction of dimethyl acid (hereinafter referred to as DMT) and 1,4-cyclohexanedimethanol (hereinafter referred to as CHDM), and polycondensation reaction, and has a very high Melting point (Tm) and very fast crystallization rate. Since the first development in 1960, due to the soft touch of PCT fibers, PCT has been mainly used in carpets. However, PCT use has gradually declined with the advent of polyamide. Since the PCT compound formulation was developed in the field of engineering plastics in the 1980s, it is only used for connectors and heat-resistant parts in the fields of electrical, electronic, automotive, etc. that require high heat resistance.

Compared with the widely used PET or PBT polyester, PCT has excellent heat resistance, Chemical resistance, moisture resistance and fluidity. In particular, PCT has a heat deflection temperature of 245 to 260 ° C and a continuous use temperature of 130 ° C to 150 ° C, so commercial non-fully aromatic polyesters, excluding liquid crystal polyesters, PCT is the only alternative metal Engineering plastics are super engineering plastics, such as polyamide, polyphenylene sulfide, and liquid crystal polymers. Especially, compared with other polymer resins such as polyamide or the like, PCT has very excellent color stability and very low water absorption, therefore, it can be effectively applied to high-temperature surface mount technology (surface Mount technology), and in the process of using the product, it is continuously exposed to heat and light in the housing or the electronic material of the LED reflector (light emitting diode).

US Patent No. 5106944 discloses the use of DMT and CHDM as the main raw materials, A method for preparing PCT with titanium alkoxide and alkaline earth metal salt as a catalyst, and US Patent No. 5124388 discloses a technique for improving PCT copolyester and PCT copolyester / polycarbonate by using hindered phenolic stabilizers The color of the ester blend. However, in these patents, germanium compounds are not used as catalysts.

In addition, U.S. Patent No. 5596068 discloses a germanium compound through the use of antimony compounds Compound and phosphorus compound to produce polyester resin with thick walls of high transparency and neutral color. However, the The patent is characterized by including 0.5 to 15% by weight of CHDM, and the resin is very different from PCT resin. In particular, there is no mention of a catalyst using germanium that significantly improves its color and light reflectivity.

US Patent No. 4972015 discloses a thin-walled, thermoformed, thermoset product, It is through the use of PCT and PCT copolyesters with an inherent viscosity of 0.7 to 1.1, and US Pat. No. 5,242,967 discloses a method for improving the crystalline properties of PCT by adding aliphatic polyesters. In addition, U.S. Patent No. 4,895,732 discloses a PCT compound formulation added with linear alcohol and glass reinforcing fibers to improve the crystallization characteristics and strength of PCT.

However, the traditional technique is only recommended to improve the crystallization characteristics and appearance in the compounding step The color composition does not report a preparation method that can substantially improve the color stability and thermal stability of PCT during the PCT polymerization step.

The invention provides a preparation method of polycyclohexane terephthalate resin having excellent color stability and improved thermal stability.

According to one aspect of the present invention, a method of preparing a polycyclohexane terephthalate resin includes the steps of injecting a titanium compound and a germanium compound as a catalyst into a mixture of a diol compound and a dicarboxylic acid with stirring And the esterification reaction and the polycondensation reaction were carried out, and the titanium atom content of the titanium compound injected was 20 ppm or less based on the weight of the final polycyclohexane terephthalate resin.

In addition, based on the weight of the final polycyclohexane terephthalate resin, the germanium atom content of the injected germanium compound is 30 to 1,000 ppm.

In the above, the diol compound may include cyclohexanedimethanol (CHDM).

Here, the diol compound may further include one or more selected from the group consisting of ethylene glycol, diethylene glycol, 1,4-butanediol, 1,3-propanediol, and neopentyl glycol.

In the above, the dicarboxylic acid may include terephthalic acid (TPA) or dimethyl terephthalic acid (DMT).

Herein, the dicarboxylic acid may further include one or more selected from isophthalic acid (IPA), The group consisting of naphthalene 2,6-dicarboxylic acid (2,6-NDA), dimethyl isophthalic acid (DMI) and dimethyl naphthalene 2,6-dicarboxylic acid (2,6-NDC) in.

Further, the titanium compound may be selected from titanium dioxide, titanium chelate, tetra-n-propyl titanate Ester, tetraisopropyl titanate, tetra-n-butyl titanate, tetraisobutyl titanate, and butyl-isopropyl titanate.

In addition, the germanium compound may be germanium dioxide.

In addition, the preparation method may further include a step of injecting a phosphorus-based stabilizer.

Here, the phosphorus-based stabilizer may be selected from triethyl phosphate, trimethyl phosphate, triphenyl Phosphoric acid ester, triethylphosphonoacetate, phosphoric acid, and phosphorous acid.

According to another aspect of the present invention, after heat treatment at 150 ° C. for 1 hour, the parylene The cyclohexane dimethyl formate resin may have an intrinsic viscosity of 1.10 deciliters per gram or less, a color L value of 87 or higher, and a color b value of 4 or lower.

According to another aspect of the invention, the polycyclohexane terephthalate resin has titanium The atomic content is 20 ppm or less, based on the weight of the final polycyclohexane terephthalate resin.

In the above, based on the weight of the final polycyclohexane terephthalate resin, the original germanium The sub-content is 30 ~ 1,000ppm.

In addition, the phosphorus compound may further include phosphorus atoms in a content of 30 to 1,000 ppm, Based on the weight of the final polycyclohexane terephthalate resin.

The preparation method of the polycyclohexane terephthalate resin according to the present invention can be used for Preparation of one with excellent degree of polymerization, color and light reflectivity, and with significantly improved thermal stability Polycyclohexane terephthalate resin, and the polycyclohexane terephthalate resin according to the present invention, are suitable materials for LED housings.

Best practice

The present invention can be variously modified and can have various embodiments. Specific embodiments of the present invention will be described in detail in the embodiments. However, the present invention is not limited to specific embodiments, and it can be understood that the present invention includes any modifications, equivalents, or alternatives included in the spirit and scope of the present invention. In the description of the present invention, if the detailed description in the related disclosed technology makes the present invention unclear, it will not be presented.

The present invention provides a method for preparing polycyclohexane dimethyl terephthalate resin, including the steps of injecting a titanium compound and a germanium compound as a catalyst into a mixture of a diol compound and a dicarboxylic acid under stirring, and The esterification reaction and the polycondensation reaction were carried out, and the titanium atom content of the injected titanium compound was 20 ppm or less based on the weight of the final polycyclohexane terephthalate resin.

Further, the present invention provides an intrinsic viscosity of 1.10 deciliters per gram (dl / g) or less after heat treatment at 150 ° C for 1 hour, a color L value of 87 or higher, and a color b value 4 or lower polycyclohexane terephthalate resin.

At the same time, the present invention provides a polycyclohexane terephthalate resin having a titanium atom content of 20 ppm or less based on the weight of the final polycyclohexane terephthalate resin.

Hereinafter, the preparation method of the polycyclohexane terephthalate resin and the polycyclohexane terephthalate resin according to the embodiment of the present invention will be described in more detail.

In general, non-fully aromatic polyester resins are generally polymerized from dicarboxylic acid and diol compounds according to methods known in the art. The steps of the preparation method of the aromatic polyester resin may include (A) mixing a dicarboxylic acid compound, a diol compound, and a phosphorus-based stabilizer compound to perform an esterification reaction, (B) adding a catalyst compound to the esterification reaction Among the obtained results, a polycondensation reaction is performed, (C) the results of the polycondensation reaction are extruded to prepare pellets, and if necessary, (D) the pellets are crystallized to Line solid phase polymerization.

According to an embodiment of the present invention, a polycyclohexane terephthalate tree is provided The preparation method of the fat includes the steps of injecting a titanium compound and a germanium compound as a catalyst into a mixture of a diol compound and a dicarboxylic acid under stirring, and performing an esterification reaction and a polycondensation reaction, and the final polyparaphenylene terephthalate The titanium atom content of the injected titanium compound is 20 ppm or less based on the weight of cyclohexane dimethyl formate resin.

Method for preparing polycyclohexane terephthalate resin according to the present invention, its characteristics The titanium compound and the germanium compound are used as catalysts, the titanium atom content of the injected titanium compound is 20 ppm or less based on the weight of the final polycyclohexyl terephthalate resin, and the final poly Based on the weight of cyclohexane dimethyl phthalate resin, the germanium atom content of the injected germanium compound is 30 to 1,000 ppm.

Due to the addition of germanium atoms, the color improvement effect can be achieved more effectively. If germanium If the content of atoms is less than 30 ppm, the color improvement effect is not perceptible. If the content of germanium atoms exceeds 1000 ppm, side reactions may occur, which may remain in the polymer and increase the haze value.

In the above, the diol compound may contain cyclohexanedimethanol (CHDM), and may It further comprises one or more selected from the group consisting of ethylene glycol, diethylene glycol, 1,4-butanediol, 1,3-propanediol and neopentyl glycol. That is, the diol compound generally refers to 1,4-cyclohexanedimethanol, but may further contain a small amount of one or more selected from ethylene glycol, diethylene glycol, 1,4-butanediol, 1,3- Propylene glycol, and neopentyl glycol.

Meanwhile, the dicarboxylic acid may include terephthalic acid (TPA) or dimethyl terephthalic acid (DMT), and may also include one or more selected from isophthalic acid (IPA), naphthalene 2,6-dicarboxyl The group consisting of acid (2,6-NDA), dimethyl isophthalic acid (DMI) and dimethyl naphthalene 2,6-dicarboxylic acid (2,6-NDC). That is, the dicarboxylic acid or its derivative generally refers to terephthalic acid (TPA) or dimethyl terephthalic acid (DMT), but may also include a small amount of isophthalic acid (IPA), 2,6-Naphthalene dicarboxylic acid (2,6-NDA), dimethyl isophthalic acid (DMI), dimethyl naphthalene 2,6-dicarboxylic acid (2,6-NDC).

Furthermore, according to the preparation method of the present invention, terephthalic acid (TPA) and One of dimethyl terephthalic acid (DMT) is used as the amount of dicarboxylic acid of 80 mole% or more, based on the moles of total acid, and preferably cyclohexanedimethanol (1, 4-cyclohexanedimethanol) as an amount of 80 mole% or more in the diol compound, based on the total number of moles of the diol compound. If the content is less than the above molar%, the physical properties of the polyester will be very different from that of PCT. Therefore, it is difficult to use this polyester as an application suitable for the development of crystalline PCT resin.

In the present invention, the titanium compound is used as a catalyst, and the titanium compound may be selected from titanium Oxide, titanium chelate, tetra-n-propyl titanate, tetra-isopropyl titanate, tetra-n-butyl titanate, tetra-isobutyl titanate, and butyl isopropyl titanate Formed groups.

In addition, based on the weight of the final polycyclohexane terephthalate resin, the injected titanium The titanium atom content of the compound is 20 ppm or less. The content is limited to the above range because too much content of titanium will cause side reactions, the color will deteriorate, and the molecular weight will be greatly reduced during processing.

The germanium compound may be germanium dioxide, and the final polycyclohexane terephthalate tree Based on the weight of the grease, the germanium atom content of the injected germanium compound is 30 to 1,000 ppm. If the content of germanium atoms is less than 30 ppm, the color improvement effect is not perceptible. If the content of germanium atoms exceeds 1000 ppm, side reactions may occur, which may remain in the polymer and increase the haze value.

Furthermore, the phosphorus-based stabilizer can be further added to the mixture of the diol compound and the dicarboxylic acid Compound. The phosphorus-based stabilizer is preferably injected at the initial stage of the esterification reaction, more preferably, before the esterification reaction. Preferably, the content of phosphorus atoms injected into the stabilizer is within 30 ppm, based on the weight of the final polycyclohexane terephthalate resin. If the content of the phosphorus-based stabilizer is greater than 30 ppm, there will be problems that the color of the polymer becomes poor, the activity of the catalyst decreases, and the reaction time and degree of polymerization are increased.

Here, the phosphorus-based stabilizer may be selected from the group consisting of triethyl phosphate, trimethyl phosphate, triphenyl phosphate, triethylphosphonoacetate, phosphoric acid, and phosphorous acid

In addition, in the present invention, the esterification reaction may be similar to that known in the art It is carried out under the reaction conditions, preferably, at a temperature of 230-290 ° C and a pressure of 0.0-3.0 kg / cm 2 for 4-10 hours. In addition, preferably, the system is configured to remove water immediately during the esterification reaction.

At the same time, the polycondensation reaction can be carried out at a temperature of 290-320 ° C and a pressure of 0.1-2.0 Torr 100 to 300 minutes under conditions. In addition, it is preferable that the system is configured to immediately remove cyclohexanedimethanol and by-products generated during the polycondensation reaction.

The solid phase reaction can be at a temperature of 230-270 ° C and a vacuum of 0.2 to 2.0 Torr, Or under nitrogen atmosphere.

At the same time, most polymers have color after polymerization. Especially, when the polymerization process is very After being exposed to excessive heat for a long time, the color of the polymer material becomes dark yellow due to pyrolysis reaction and oxidation. Because the visual appearance of the product, including color, is important, the color of the polymer material is an important quality factor.

According to the preparation method of the polycyclohexane terephthalate resin of the present invention The PCT resin, after heat treatment at 150 ° C for 1 hour, has an intrinsic viscosity of 1.10 dL / g or less, a color L value of 87 or higher, and a color b value of 4 or lower.

Meanwhile, according to another aspect of the present invention, polycyclohexane terephthalate resin, It has a titanium atom content of 20 ppm or less based on the weight of the final polycyclohexane terephthalate resin. If the titanium content exceeds 20 ppm, it will cause side reactions, the color will deteriorate, and the molecular weight will be greatly reduced during processing.

In addition, polycyclohexane terephthalate resin can also have 30 ~ 1,000ppm The content of germanium atoms is based on the weight of the final polycyclohexane terephthalate resin. If the content of germanium atoms is less than 30 ppm, the color improvement effect is not perceptible. If the content of germanium atoms exceeds 1000 ppm, side reactions may occur and may remain in the polymer, increasing the haze value.

detailed description

The preferred embodiments of the present invention will be described in detail below. However, these examples For illustrative purposes only, it is not because these examples limit the scope of the present invention.

example 1

55 kg of 1,4-cyclohexanedimethanol (trans 70%), 48 kg of terephthalic acid, 7 Grams of triethyl phosphate, 10 grams of titanium oxide catalyst (trade name: Hombifast PC manufactured by Sachtleben) (effective Ti ratio in the catalyst: 15%), and 11.5 grams of germanium dioxide are added to the reactor to carry out esterification At the same time, the temperature was raised to 280 ° C, and the reaction was carried out at normal pressure for 3 hours, while the polycondensation reaction of polyester was carried out at 300 ° C and a vacuum of 0.5 to 1 Torr for 150 minutes, thereby preparing PCT polymer .

Example 2

55 kg of 1,4-cyclohexanedimethanol (trans 70%), 48 kg of terephthalic acid, 7 Grams of triethyl phosphate, 10 grams of titanium oxide catalyst (trade name: Hombifast PC manufactured by Sachtleben) (effective Ti ratio in the catalyst: 15%) and 23 grams of germanium dioxide are added to the reactor for esterification reaction, Simultaneously, the temperature was raised to 280 ° C and conducted at normal pressure for 3 hours, and the polycondensation reaction of polyester was performed at 300 ° C and a vacuum of 0.5 to 1 Torr for 150 minutes, thereby preparing a polymer of PCT.

Example 3

55 kg of 1,4-cyclohexanedimethanol (trans 70%), 48 kg of terephthalic acid, 7 Grams of triethyl phosphate, 10 grams of titanium oxide catalyst (trade name: Hombifast PC manufactured by Sachtleben) (effective Ti ratio in the catalyst: 15%) and 46 grams of germanium dioxide are added to the reactor for esterification reaction, At the same time, the temperature was raised to 280 ° C, and the polycondensation reaction of the polyester was carried out at 300 ° C and a vacuum of 0.5 to 1 Torr for 150 minutes at normal pressure for 3 hours, thereby preparing a polymer of PCT.

Example 4

55 kg of 1,4-cyclohexanedimethanol (trans 70%), 48 kg of terephthalic acid, 7 Grams of triethyl phosphate and 15 grams of titanium oxide catalyst (trade name: Hombifast PC manufactured by Sachtleben) (effective Ti ratio in the catalyst: 15%) were added to the reactor to perform esterification reaction while increasing the temperature To 280 ° C., it was conducted under normal pressure for 3 hours, and the polycondensation reaction of polyester was carried out at 300 ° C. and a vacuum of 0.5 to 1 Torr for 150 minutes, thereby preparing a polymer of PCT.

Example 5

55 kg of 1,4-cyclohexanedimethanol (trans 70%), 48 kg of terephthalic acid, 7 Grams of triethyl phosphate, 10 grams of titanium oxide catalyst (trade name: Hombifast PC manufactured by Sachtleben) (effective Ti ratio in the catalyst: 15%) and 23 grams of germanium dioxide are added to the reactor for esterification reaction, Simultaneously, the temperature was raised to 280 ° C and conducted at normal pressure for 3 hours, and the polycondensation reaction of the polyester was performed at 300 ° C and a vacuum of 0.5 to 1 Torr for 150 minutes. Then, solid phase polymerization was performed at 240 ° C, thereby preparing a polymer of PCT.

Comparative example 1

55 kg of 1,4-cyclohexanedimethanol (trans 70%), 48 kg of terephthalic acid, 7 Grams of triethyl phosphate and 20 grams of titanium oxide-based catalyst (trade name: Hombifast PC manufactured by Sachtleben) (effective Ti ratio in the catalyst: 15%) were added to the reactor for esterification reaction, while raising the temperature to The polymerization was carried out at 280 ° C under normal pressure for 3 hours, and the polycondensation reaction of polyester was carried out at 300 ° C and a vacuum of 0.5 to 1 Torr for 150 minutes, thereby preparing a polymer of PCT.

Comparative example 2

55 kg of 1,4-cyclohexanedimethanol (trans 70%), 48 kg of terephthalic acid, 7 Grams of triethyl phosphate and 25 grams of titanium oxide-based catalyst (trade name: Hombifast PC manufactured by Sachtleben) (effective Ti ratio in the catalyst: 15%) were added to the reactor to perform esterification reaction while increasing the temperature To 280 ℃, under normal pressure for 3 hours, and the polycondensation reaction of polyester It was performed at 300 ° C. and a vacuum of 0.5 to 1 Torr for 150 minutes, thereby preparing a polymer of PCT.

Comparative Example 3

55 kg of 1,4-cyclohexanedimethanol (trans 70%), 48 kg of terephthalic acid, 7 Grams of triethyl phosphate and 40 grams of titanium oxide-based catalyst (trade name: Hombifast PC manufactured by Sachtleben) (effective Ti ratio in the catalyst: 15%) were added to the reactor for esterification reaction, while raising the temperature to The polymerization was carried out at 280 ° C under normal pressure for 3 hours, and the polycondensation reaction of polyester was carried out at 300 ° C and a vacuum of 0.5 to 1 Torr for 150 minutes, thereby preparing a polymer of PCT.

Comparative Example 4

55 kg of 1,4-cyclohexanedimethanol (trans 70%), 48 kg of terephthalic acid, 7 Grams of triethyl phosphate and 60 grams of titanium oxide-based catalyst (trade name: Hombifast PC manufactured by Sachtleben) (effective Ti ratio in the catalyst: 15%) were added to the reactor for esterification reaction, while raising the temperature to The polymerization was carried out at 280 ° C under normal pressure for 3 hours, and the polycondensation reaction of polyester was carried out at 300 ° C and a vacuum of 0.5 to 1 Torr for 150 minutes, thereby preparing a polymer of PCT.

Comparative Example 5

55 kg of 1,4-cyclohexanedimethanol (trans 70%), 48 kg of terephthalic acid, 7 Grams of triethyl phosphate, 15 grams of titanium oxide-based catalyst (trade name: Hombifast PC manufactured by Sachtleben) (effective Ti ratio in the catalyst: 15%) and 168.7 grams of germanium dioxide are added to the reactor for esterification reaction At the same time, the temperature was raised to 280 ° C, and the polycondensation reaction of the polyester was carried out at 300 ° C and a vacuum of 0.5 to 1 Torr for 150 minutes at normal pressure for 3 hours, thereby preparing PCT polymer.

Comparative Example 6

55 kg of 1,4-cyclohexanedimethanol (trans 70%), 48 kg of terephthalic acid, 7 Grams of triethyl phosphate, 25 grams of titanium oxide catalyst (trade name: Hombifast PC manufactured by Sachtleben) (effective Ti ratio in the catalyst: 15%) and 168.7 grams of germanium dioxide were added to the reactor to carry out esterification At the same time, the temperature was raised to 280 ° C, and the reaction was carried out at normal pressure for 3 hours, while the polycondensation reaction of polyester was carried out at 300 ° C and a vacuum of 0.5 to 1 Torr for 150 minutes, thereby preparing PCT polymer .

Experimental Example 1

The intrinsic properties of the respective PCT resins obtained in Examples 1 to 3 and Comparative Examples 1 to 7 The viscosity is measured by the following method.

The PCT resin was dissolved in o-chlorophenol to a concentration of 1.2 g / dL, and then the intrinsic viscosity was measured with a Ubbelohde viscometer. The temperature of the viscometer is maintained at 35 ° C. When the time for the solvent to flow through the viscometer (flow time) is defined as t, and the time for the solution to flow through this part is defined as t ₀ , the specific viscosity can be defined as follows:

Among them, the calculation of intrinsic viscosity is corrected by the following formula:

Where A is 0.247 Huggins ’s constant and c is 1.2 g / The concentration value in deciliters.

Experimental Example 2

The colors of the respective PCT resins obtained in Examples 1 to 3 and Comparative Examples 1 to 7, It was measured by the following method.

PCT resin is crystallized in a convection oven at 150 ° C for 1 hour, and then the colorimeter is used (colorimeter) Determine the color of PCT resin.

The CIE LAB index is used for color measurement. The CIE LAB system is defined by CIE The color space coordinate system is based on the yellow-blue and green-red relative pipes recognized by people. L * value means brightness (0 ~ 100; 0 means black, 100 means white), a * value means green-red (based on 0, +: red,-: green) and b * value means yellow-blue (based on 0, +: Yellow,-: blue).

The conditions and physical properties of the examples and the comparative examples described above are shown in Table 1 below.

As shown in Table 1, it can be seen that the method for preparing polycyclohexane terephthalate resin according to the present invention has excellent color and light reflectance when used to prepare polycyclohexane terephthalate resin However, it is suitable to use the polycyclohexyl terephthalate resin according to the present invention as an LED housing material.

Although the manner in which specific embodiments of the present invention are carried out is described in detail, those skilled in the art should understand that such description is only a preferred embodiment, and is not to be construed as limiting the scope of the present invention. Therefore, the actual scope of the invention is defined by the appended claims and their equivalents.

The above are only the preferred embodiments of the present invention, and all changes and modifications made within the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims (14)

A method for preparing polycyclohexane dimethyl terephthalate resin, which includes the steps of injecting a titanium compound and a germanium compound as a catalyst to a mixture of a diol compound and a dicarboxylic acid as a catalyst under stirring and performing esterification Chemical reaction and polycondensation reaction, in which the titanium atom content of the injected titanium compound is 20 ppm or less based on the weight of the final polycyclohexyl terephthalate resin, wherein after heat treatment at 150 ° C for 1 hour, the poly The cyclohexane dimethyl phthalate resin has a color L value of 87 or higher. The production method according to claim 1, wherein the germanium atom content of the injected germanium compound is 30 to 1,000 ppm based on the weight of the final polycyclohexane terephthalate resin. The production method according to claim 1, wherein the diol compound includes cyclohexane dimethanol (CHDM). The preparation method according to claim 3, wherein the diol compound further comprises one or more selected from the group consisting of ethylene glycol, diethylene glycol, 1,4-butanediol, 1,3-propanediol and neopentyl glycol Group. The production method according to claim 1, wherein the dicarboxylic acid includes terephthalic acid (TPA) or dimethyl terephthalic acid (DMT). The preparation method according to claim 5, wherein the dicarboxylic acid further includes one or more selected from isophthalic acid (IPA), naphthalene 2,6-dicarboxylic acid (2,6-NDA), dimethyl isophthalic acid (DMI) and dimethylnaphthalene 2,6-dicarboxylic acid (2,6-NDC). The preparation method according to claim 1, wherein the titanium compound is selected from titanium oxide, titanium chelate, tetra-n-propyl titanate, tetra-isopropyl titanate, tetra-n-butyl titanate, tetra-isobutyl titanium Acid ester, and butyl-isopropyl titanate. The production method according to claim 1, wherein the germanium compound is germanium dioxide. As in the preparation method of claim 1, the method further includes the step of injecting a phosphorus-based stabilizer. The preparation method according to claim 9, wherein the phosphorus stabilizer is selected from triethyl phosphate, trimethyl phosphate, triphenyl phosphate, triethylphosphonoacetate, phosphoric acid, and phosphorous acid Formed groups. A polycyclohexane terephthalate resin having a titanium atom content of 20 ppm or less, based on the weight of the final polycyclohexane terephthalate resin, wherein after heat treatment at 150 ° C for 1 hour , Polycyclohexane terephthalate resin has a color L value of 87 or higher. The polycyclohexane terephthalate resin of claim 11 further contains germanium atoms in a content of 30 to 1,000 ppm, based on the weight of the final polycyclohexane terephthalate resin. The polycyclohexane terephthalate resin of claim 11 further contains a phosphorus atom content of 30 to 1,000 ppm, based on the weight of the final polycyclohexane terephthalate resin. The polycyclohexane terephthalate resin as in claim 11, wherein after heat treatment at 150 ° C for 1 hour, the polycyclohexane terephthalate resin has an intrinsic viscosity of 1.10 deciliters / gram or less , And a color b value of 4 or lower.